Wearing parts for crushers

ABSTRACT

The present invention is related to wear-taking members or plates for crushing or grinding mills, for example, for cone or gyratory crushers, or for jaw crushers. The particular structure shown illustrates a gyratory crusher in which plates involving the invention are shown as surrounding a lower part of a gyrated head, and, therefore, as constituting the wear-taking part of a bowl liner. It will be understood that plates having the same general characteristics, with slightly changed form, may also be employed in connection with one or both jaws of a jaw crusher in which jaws are mounted for relative movement, whereby to define between them a crushing cavity. It will be understood that crushing parts take tremendous wear, and wear away rapidly. A major purpose of the invention is to provide a wear-taking part and a method of making it which permits the use of hard but brittle metals.

United States Patent [72] Inventor Erik Arne Sabel Box 128, Ojebyn, Sweden [21] Appl. No. 843,576

[22] Filed July 22, 1969 [45] Patented Oct. 12, 1971 M [54] WEARING PARTS FOR CRUSHERS 10 Claims, 4 Drawing Figs.

[52] US. Cl 241/291, 241/295, 241/299 [51] Int. Cl B02c 2/00,

B02c 1/00 [50] Field of Search 241/291-300 [56] References Cited UNITED STATES PATENTS 1,494,265 5/1924 Martindale 241/299 3,503,564 3/1970 Adam 241/299 Primary ExaminerDonald G. Kelly Att0rneyParker, Carter and Markey ABSTRACT: The present invention is related to wear-taking members or plates for crushing or grinding mills, for example, for cone or gyratory crushers, or for jaw crushers. The particular structure shown illustrates a gyratory crusher in which plates involving the invention are shown as surrounding a lower part of a gyrated head, and, therefore, as constituting the wear-taking part of a bowl liner. It will be understood that plateshaving the same general characteristics, with slightly changed form, may also be employed in connection with one or both jaws of a jaw crusher in which jaws are mounted for relative movement, whereby to define between them a crushing cavity. It will be understood that crushing parts take tre mendous wear, and wear away rapidly. A major purpose of the invention is to provide a wear-taking part and a method of making it which permits the use of hard but bn'ttle metals.

l WEARING mars ros causiisas SUMMARY OF THE INVENTION in jaw crushers. This metal, although tough, lacks the hardness of some other materials and wears away at a more rapid rate than is desirable. This causes a shorter life and the necessity of more frequent stoppage of the crusher for replacement. The hard steels, which have the highest wear resistance, are prevailingly brittle, and their brittleness involves the risk of the formation of cracks or breaks. This brittleness has hitherto constituted a very serious obstacle to the utilization of metals having the highest wear resistance and thereby having a longer wearing life.

By means of the present invention, the drawback of brittleness has been overcome by using a body or plate formed or poured of a metal having a very high resistance to wear. I propose to use a hard and brittle metal which is poured about a retaining structure, which may, for example, be formed of rods of a different metal. This forms an internal frame or retaining structure having great tensile strength and great resistance to fracture, but which is completely enclosed within an outer matrix of the brittle metal. Whereas, as a matter of convenience, I may talk in tenns of a reinforcing structure, it will be realized that this internal structure may equally well be described as a retaining or stabilizing structure which becomes of primary effectiveness in the event of cracking or breakage of the brittle metal body or matrix. As will appear below, the body or matrix, which forms the wearing part, is cast from metals or alloys having originally, or by treatment, a high- Brinnell hardness. The metal employed is preferably cast about a suitably arranged retaining or stabilizing structure, which, as will appear below, is coated with a suitable coating effective to prevent it from being sintered to or joined directly to the metal of the surrounding matrix or wearing part. Since the enclosed stabilizing or retaining structure is separated by a suitable coating from any sintering to or joinder with the outer brittle metal of the wearing part, it is not affected by cracking or breakage of the outer brittle matrix or body. In the event of such breakage, since there is very little clearance between the coating of the inner retaining structure and the abutting, surrounding mass of the matrix or outer structure, cracking or breakage of the matrix or outer structure does not result in any damaging separation of the parts formed by the breakage.

An advantage of the present invention is that the retaining or reinforcing rod or member is protected from the extreme load, caused by extreme shock or the entry of tramp metal into the crushing cavity, because it is not fused or joined interlinearly to the matrix material. If there is any fusion or joinder of the rods to the surrounding matrix then, even though the rods are quite large and are made of high impact-resisting material, they would be ruptured, with the matrix, if actually subjected to full shock loads. Whether or not the rod structure is of tougher metal, or is of a metal of greater tensile strength than the matrix, the effect of the isolation or separation between matrix and retaining structure is to protect the retaining structure from rupture with the matrix. Even if the matrix is cracked or broken, the retaining structure remains intact, and operates to hold the wearing parts together. Thus, although a brittle metal bowl liner or mantle or jaw plate may be cracked, the inner retaining structure prevents any damaging separation along the crack or cracks.

BRIEF DESCRIPTION OF THE DRAWINGS The wearing part may be various shapes, but I illustrate herein a specific example.

Referring to the drawings:

FIG. I is a vertical section, with parts in elevation, of a gyrated head crusher in which a plate made in accordance with my invention is shown in section;

FIG. 2 is a vertical section through such a plate, on a larger scale;

FIG. 3 is a view of the rear face of such a plate, with the internal parts indicated in dotted lines; and

FIG. 4 is a top view of such a plate, also with inner parts indicated in dotted line.

DESCRIPTION OF THE PREFERRED EMBODIMENT Like parts are indicated by like symbols throughout the specification and drawings.

Referring, first, to FIG. 1, 1 generally indicates annuli which, together, form the outer shell or bowl of a gyratory crusher. 2 is a supporting annulus for the upper annuli. 3 is a frame member through a flange of which pass tension members or securing bolts 4, whereby the assembled outer bowl of a gyratory crusher is held together. 5 illustrates s gyrated head which, through any suitable actuating means, not forming part of the present invention, is gyrated within the bowl formed by the annuli 1. It is customary to employ removable wear-taking members for the head and bowl. As a matter of illustration, however, I indicate only wear-taking members for the bowl itself, and, as a matter of illustration, I apply these only to the lower part of the crushing cavity, at the convergence between the opposed crushing members, where there is a maximum crushing stress. It will be understood, however, that my invention may be applied throughout the entire bowl, or, with varying forms of mantle, throughout the crushing surface of the head.

Considering the specific plates herein shown, as applied, for example, to the lower part of the crushing cavity, I illustrate a body or matrix, generally indicated as 10, which may be of a casting of perlitic, carbidic white cast iron, or martensitic, carbidic, chromenickel alloyed cast iron, sometimes known in the trade as Nihard. Castings from such metals are known to be brittle and hard, and to have good wear characteristics. It will be understood, of course, that the list is not all-inclusive, and other brittle metals may be employed.

It will be understood that the plate body, casting or matrix 10 has embedded within it a retaining structure, shown as formed with generally upright portions or components I I, l2, l3 and 14, these components being connected by suitable bends and cross portions 15, I6 and 17. As a matter of convenience, the upper end of the portion 11 is shown as abutting the lower side of the cross portion 16, to which it may, if desired, be welded. Likewise, the cross portion 17 is shown as having a terminal, downwardly extending end 18, the lower part of which abuts, and may, if desired, be welded to a bend of the cross portion 16. It will be understood that this reinforc ing, or retaining, or positioning structure may be of rod stock, for example, from steel of high-tensile strength and fracture resistance. The rod can be made of mild steel, special steel or any suitable alloy; however, in order to end with rods in the finished piece that retain their impact properties, it may be necessary to limit the carbon content to some predetermined level depending on the specific alloy and the environment to which the rerods are exposed during the manufacturing process. With the so-called Nihard matrix castings, it has been found necessary to limit the carbon content to a maximum of about 0.015 percent. Rods of C-l008 (C about 0.08 percent) have been used and gave much better results than rods with 0.20 to 0.30 percent carbon or so-called 20 C. steel rods.

The retaining structure is spaced or separated from the subsequently cast matrix by a thin layer, which may be of a mixture of plastic and sand. Whereas I have not illustrated this layer in the drawings, it will be understood that this thin layer is applied throughout the outer surface of the inner structure in such fashion as to prevent any direct contact of the inner retaining structure with the outer matrix. Thus any fusing or direct bonding of the two metals is prevented, and the retaining structure is independent of and may move within the outer structure, although, with the mixture of plastic and sand, there is a direct contact, nonmetallic, between the retaining structure and the outer matrix. This contact is sufficiently tight to prevent any separation of pieces or parts in the event that the outer matrix 10 is cracked, so that there will be no damaging separation or division of the matrix. In actual practice, the thickness of the coating on the rods is from about one thirtysecond inch to three thirty-seconds inch, usually about onesixteenth inch, and there can be a slight separation of the pieces after cracking; in practice, the rods hold the pieces sufficiently well in place to allow for continued operation of the liner generally to the completion of its normal life. In any event, the rods result in an extended life of the cracked piece.

Prior to the casting of the matrix or outer body 10 about the inner retaining structure the following treatment may be used. The inner structure is preferably annealed, and blasted, pickled and heated in an oven to a temperature of 250 to 300 C. At such a temperature the retaining structure is placed in a box more or less filled with a mixture which may be, for example, of about 93 percent sand of fineness No. 110 (American Foundryman Society) and about 7 percent powdered resin such as phenolformaldehyde molding powder. The The box contents may then be rotated and agitated. The heat of the retaining structure softens the resin, which, in turn, causes the sand to adhere and more resin to adhere to the adhered sand which has by that time become heated. Thus a layer of mixed sand and resin is built up on the retaining structure to a thickness ranging, for example, from about one-half millimeter to millimeters, according to the mass of the retaining elements and the duration of agitation, as well as the temperature of the retaining structure when it is placed in the box. After the retaining structure is taken from the box it is then baked to a hard crust at about 200 to 400 C. Alternatively, as another example, the rerods are dipped in a core oil, such as GE Smith Core Oil, and sand is sprinkled on evenly on the rods. In one case, No. 420 silica sand was used with good results. A catalyst such as AP4 may be added to the core oil. In one case, 4 percent of AP-4 weight of core oil was added with good results. The rerod is baked at from 300 to 450 F., until the coating is hard. If a thicker coating is desired, the procedure can be repeated any number of times. Although the above procedure gives good results, it is an example only and not intended to be a limitation.

The formation of this crust and its adherence to the internal or retaining structure prevents the cast metal of the matrix 10 from becoming sintered onto or fused to the retaining structure or reinforcement. Thereby relative movement of the cooling and shrinking matrix with respect to the retaining structure is permitted, so that internal stresses due to he presence within the matrix of the retaining structure are minimized. The hot casting metal which is of a temperature sufficient partially to decompose part of the resin, where resin is used, produces an amount of gas effective to form a film between the casting metal and the bulk of the crust, and so retards further decomposition. However, there is a minimal clearance between the retaining structure and the surrounding matrix which is cast about it. The composite separating layer, of at least partially decomposed resin and sand, is yieldable enough, in the casting, to allow relative movement of the reinforcement and the casting or matrix proper. However, when the retaining structure has the brittle outer body or matrix cast about it, there is, in effect, no clearance between the separating layer of the retaining structure and the brittle casting itself.

At the time of casting the retaining structure, as shown, for example, in FIGS. 2 to 4, inclusive, may be positioned generally horizontally. It will be understood that, if desired, the retaining structure has been welded, as above mentioned, in order to provide a substantially stable internal structure. This structure, if the shape of the matrix demands, may be slightly bent, as at X in FIG. 2. If desired, it may be strengthened by small internal blocks 20, 21. As a matter of convenience, supports or plugs, indicated at 22, 23 and 24,

may be put on a suitable supporting surface to support the retaining structure in proper relationship to the rear or bottom surface 10a of the matrix. This rear face may also be formed, if desired, with spacing lugs 25, whereby, when in use, it is spaced slightly inwardly from the ring I which it outwardly abuts. These lugs or spacer connections 25 may be positioned as desired. In FIG. 3 they are shown at or near the corners of the plate. Likewise, I prefer to form a pouring aperture or recess 26 through which a suitable backing material may conveniently be poured into the space between the matrix 10 and the outer bowl ring 1. Since we are dealing with heavy masses of metal which have to be conveyed to position, it is convenient to insert in the matrix 10 any suitable preformed lifting ring 28, with its central aperture 29 and its annular portion 30, which interlock with the matrix when the matrix 10 is poured, and which can receive a lifting tackle.

A primary purpose of the above-described retaining structure is to maintain the brittle outer body or matrix intact. If it cracks, the brittle metal is held together along the faces of the cracks by the above-described retaining structure. If the cracking results in an actual separation into parts, these parts are held against each other as a unitary body by the retaining structure, which is effective to prevent substantial or damaging relative movement.

With reference, for example, to FIG. 2, any desired number of spacers or supports 22, 23, 24 may be employed. Any suitable mold may be employed. Any suitable rod may be employed, but it will be understood that it should be of relatively high-tensile strength, and should be resistant to fracture. For example, the range of ultimate tensile strength may be as low as 45,000 or less, and as high as 100,000 or more. When the matrix or outer body has been poured about the retaining structure, the result is a mantle of brittle metal which is internally reinforced, from edge to edge and from end to end, by a reinforcement or retainer, which may be unitary, and which is of greater tensile strength than the outer wear-resistant and brittle material.

It will be clear from FIGS. 1 and 2 that the above-described internal retaining structure is spaced within the matrix 10 by a relatively short distance separating it from the nonworking rear face 10a. As is clear from FIG. 2, a very substantial mass of metal is effective to take wear, and, until this mass has been worn down or worn away, the internal retaining structure is completely surrounded. The amount of metal between the retaining structure and the rear face of the matrix is inconsiderable, and waste of such metal is unimportant.

It will be realized that whereas I have described a practical and operative article and a method of making it, nevertheless, many changes may be made without departing from the spirit of the invention. I therefore wish the description and drawings to be taken as in a broad sense illustrative or diagrammatic rather than as limiting me to the specific structure shown. Whereas I have shown the invention as applied to a wear-taking plate for a crusher with a gyrated head, it will be understood that it may be employed in wear-taking plates for jaw crushers. Whereas I have shown a retaining structure consisting of a single bent rod formed with horizontal and vertical positions, it will be understood that I may employ reinforcing structures formed of more than one rod portion or piece. It is also a matter of choice whether the reinforcement is welded into a fixed form or whether I wish to rely on the inclusion of the retaining structure within the matrix to maintain it in proper position. Whereas I show plugs or connectors for supporting the retainer structure in proper position during the pouring of the matrix about it, any other suitable positioning means may be employed.

Iclaim:

1. In a crusher plate for use in crushers wherein opposed crushing members are mounted for relative movement, a matrix of hard but brittle metal fonned to be removably positioned in relation to a support, and a retaining structure within said matrix, constituted by a metal of substantially greater tensile strength and substantially less brittleness than the matrix,

said retaining structure being enclosed within the matrix by the casting of the matrix thereabout, said retaining structure being substantially closer to the supporting rear face of the matrix than to its work engaging crushing face, the proportioning of the matrix and the spacing of the retaining structure in relation to it being such that the matrix, during its normal crushing life, continuously surrounds the retaining structure, the retaining structure including portions extending lengthwise and transversely of the matrix, and a separating layer of slightly yieldable material between the retaining structure and the matrix, adapted to permit relative movement of the retaining structure and the matrix, while preventing fixed union of the retaining structure and the body, the separating layer being in contact with and intermediate the retaining structure and the surrounding matrix.

2. The structure of claim 1 characterized in that the matrix is constituted by a metal having a Brinnell hardness number as high as 400, the retaining structure being of steel.

3. The structure of claim 1 characterized in that the separating layer is constituted by sand and a small amount of a plastic binder therefor.

4. The structure of claim 1 characterized in that the separating layer is constituted by sand and core oil with which small about of a catalyst or catalysts may be employed to alter viscosity and setting characteristics of the mixture.

5. The structure of claim 1 characterized in that the retaining structure is constituted by a metal rod portion extending lengthwise and transversely adjacent the side edges and ends of the matrix.

6. The structure of claim 1 characterized in that the retaining structure is constituted by a metal rod including portions extending lengthwise and transversely adjacent the side edges and ends of the matrix, and including additional rod portions more remote from but generally parallel with the side edges of the matrix.

7. The structure of claim 1 characterized by and including spacer projections extending from the rear face of the matrix, whereby to space the matrix from an abutting portion of the crusher, to define a space into which backing material may readily be poured.

8. The structure of claim 1 characterized by and including spacing projections extending from the rear face of the matrix, whereby to space the matrix from an abutting portion of the crusher, to define a space into which the backing material may readily be poured, the matrix having also an enlarged pouring space adjacent its upper edge formed and adapted to direct fluid backing material into the space between the rear face of the matrix and the adjacent surface of the support.

9. The structure of claim 1 characterized in that the retaining structure is constituted by a continuous metal rod including portions extending lengthwise and transversely or the matrix, said rod being secured in a fixed form.

10. As a new article of manufacture, a wearing plate for crushers which includes a body of hard and relatively brittle wear-resistant metal, said body having top, bottom and side edges, and a working face adapted to be opposed to particles to be crushed and an opposite backing face adapted to be opposed to a backing member in the crusher, said body having embedded therein a completely surrounded retaining structure including a retaining framework of a metal having a relatively high-tensile strength and being relatively resistant to fracture, said framework being located substantially closer to the backing face than to the working face, the retaining structure being not fused to and being, therefore, separated from the body, whereby to permit limited relative movement, said framework including frame portions extending along and within the side edges and the top and bottom edges of the plate, and portions extending across the plate, whereby to be effective to hold all parts of the plate against relative movement in the event of cracking or breakage. 

1. In a crusher plate for use in crushers wherein opposed crushing members are mounted for relative movement, a matrix of hard but brittle metal formed to be removably positioned in relation to a support, and a retaining structure within said matrix, constituted by a metal of substantially greater tensile strength and substantially less brittleness than the matrix, said retaining structure being enclosed within the matrix by the casting of the matrix thereabout, said retaining structure being substantially closer to the supporting rear face of the matrix than to its work engaging crushing face, the proportioning of the matrix and the spacing of the retaining structure in relation to it being such that the matrix, during its normal crushing life, continuously surrounds the retaining structure, the retaining structure including portions extending lengthwise and transversely of the matrix, and a separating layer of slightly yieldable material between the retaining structure and the matrix, adapted to permit relative movement of the retaining structure and the matrix, while preventing fixed union of the retaining structure and the body, the separating layer being in contact with and intermediate the retaining structure and the surrounding matrix.
 2. The structure of claim 1 characterized in that the matrix is constituted by a metal having a Brinnell hardness number as high as 400, the retaining structure being of steel.
 3. The structure of claim 1 characterized in that the separating layer is constituted by sand and a small amount of a plastic binder therefor.
 4. The structure of claim 1 characterized in that the separating layer is constituted by sand and core oil with which small about of a catalyst or catalysts may be employed to alter viscosity and setting characteristics of the mixture.
 5. The structure of claim 1 characterized in that the retaining structure is constituted by a metal rod portion extending lengthwise and transversely adjacent the side edges and ends of the matrix.
 6. The structure of claim 1 characterized in that the retaining structure is constituted by a metal rod including portions extending lengthwise and transversely adjacent the side edges and ends of the matrix, and including additional rod portions more remote from but generally parallel with the side edges of the matrix.
 7. The structure of claim 1 characterized by and including spacer projections extending from the rear face of the matrix, whereby to space the matrix from an abutting portion of the crusher, to define a space into which backing material may readily be poured.
 8. The structure of claim 1 characterized by and including spacing projections extending from the rear face of the matrix, whereby to space the matrix from an abutting portion of the crusher, to define a space into which the backing material may readily be poured, the matrix having also an enlarged pouring space adjacent its upper edge formed and adapted to direct fluid backing material into the space between the rear face of the matrix and the adjacent surface of the support.
 9. The structure of claim 1 characterized in that the retaining structure is constituted by a continuous metal rod including portions extending lengthwise and transversely or the matrix, said rod being secured in a fixed form.
 10. As a new article of manufacture, a wearing plate for crushers which includes a body of hard and relatively brittle wear-resistant metal, said body having top, bottom and side edges, and a working face adapted to be opposed to particles to be crushed and an opposite backing face adapted to be opposed to a backing member in the crusher, said body having embedded therein a completely surrounded retaining structure including a retaining framework of a metal having a relatively high-tensile strength and being relatively resistant to fracture, said framework being located substantially closer to the backing face than to the working face, the retaining structure being not fused to and being, therefore, separated from the body, whereby to permit limited relative movement, said framework including frame portions extending along and within the side edges and the top and bottom edges of the plate, and portions extending across the plate, whereby to be effective to hold all parts of the plate against relative movement in the event of cracking or breakage. 